Styjun

I am using the plugin to authenticate WordPress using api-rest : JWT Authentication for WP REST API

From the request to the server I get the following answer:

 "token": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwczpcL1wvbWlob3N0Lm9yZ1wvcHJ1ZWJhcyIsImlhdCI6MTU1MzcyNDM4MSwibmJmIjoxNTUzNzI0MzgxLCJleHAiOjE1NTQzMjkxODEsImRhdGEiOnsidXNlciI6eyJpZCI6IjIifX19.rgi5Q2c8RCoHRp-lJiJN8xQaOavn9T_q8cmf8v1-57o",
 "user_email": "abc@test.com",
 "user_nicename": "test",
 "user_display_name": "Test"

So far everything works fine, but I need to know the user ID.

I have read that the token is coded in base64 and within this is the ID. Trying to decode, I see if the ID that I need is there.

In swift with this function I decode the token, but I can not get the dictionary ID.

func decode(_ token: String) -> [String: AnyObject]? 
 let string = token.components(separatedBy: ".")
 let toDecode = string[1] as String


 var stringtoDecode: String = toDecode.replacingOccurrences(of: "-", with: "+") // 62nd char of encoding
 stringtoDecode = stringtoDecode.replacingOccurrences(of: "_", with: "/") // 63rd char of encoding
 switch (stringtoDecode.utf16.count % 4) 
 case 2: stringtoDecode = "(stringtoDecode)=="
 case 3: stringtoDecode = "(stringtoDecode)="
 default: // nothing to do stringtoDecode can stay the same
 print("")
 
 let dataToDecode = Data(base64Encoded: stringtoDecode, options: [])
 let base64DecodedString = NSString(data: dataToDecode!, encoding: String.Encoding.utf8.rawValue)

 var values: [String: AnyObject]?
 if let string = base64DecodedString 
 if let data = string.data(using: String.Encoding.utf8.rawValue, allowLossyConversion: true) 
 values = try! JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments) as? [String : AnyObject]
 
 
 return values

The dictionary that returns this function is:

["iss": https://myhost.me/test, "exp": 1554235730, "nbf": 1553630930, "iat": 1553630930, "data": 
 user = 
 id = 2;
 ;
]

How do I get the ID from this dictionary?

Your code is pretty unswifty.

Basically don't use NS... classes in Swift if there is a native equivalent and a JSON dictionary is always value type ([String:Any]).

I recommend to add an Error enum, make the function can throw, decode the serialized token with Decodable and return the Token instance on success

struct Token : Decodable 
 let data : UserData

 struct UserData : Decodable 
 let user : User

 struct User : Decodable 
 let id : String
 
 

You are encouraged to keep the parameter label in the method declaration

enum TokenError : Error 
 case invalidJWTFormat, invalidBase64EncodedData


func decode(token: String) throws -> Token 
 let components = token.components(separatedBy: ".")
 guard components.count == 3 else throw TokenError.invalidJWTFormat 
 var decodedString = components[1]
 .replacingOccurrences(of: "-", with: "+")
 .replacingOccurrences(of: "_", with: "/")

 while decodedString.utf16.count % 4 != 0 
 decodedString += "=" 
 
 guard let decodedData = Data(base64Encoded: decodedString) else throw TokenError.invalidBase64EncodedData 
 return try JSONDecoder().decode(Token.self, from: decodedData)

and call it

do 
 let userID = try decode(token: "eyJ0eXAi.....").data.user.id
 catch print(error)